Nick is not exactly a bad guy. But in David Fincher’s twisted thriller, he’s not exactly good, either. The media circus that swells after Amy mysteriously vanishes immediately frames her husband as a possible murder suspect. And not without reason. He seems as if he is guilty of something, even if he simply lacks the smarts and social skills to put on a sincere front in a public forum. He feels so awkward, he even can’t stop himself from smugly smiling while posing for a photo in front of a poster of his missing wife. It’s little wonder that Ben Affleck, 42, is getting some of the best notices of his career as Nick. It’s as if he were destined to portray this sort of callow schnook who relies a little too much on his good looks to sail through life. Says Variety critic Justin Chang: “It’s a tricky turn, requiring a measure of careful underplaying and emotional aloofness, and he nails it completely.”

Funny how everyone expected that British actress Rosamund Pike, up until now barely known outside her homeland, would be the discovery in “Gone Girl” – and indeed, she has earned her share of raves. But Affleck — who has had more success as a director of late, including “Argo’s” Oscar win as 2012’s best picture — is the real surprise.

Even he sounds re-invigorated by the change of pace that “Gone Girl” provided. As Affleck revealed in an NPR interview, “The whole idea of likability was sort of thrown out of the window. And I thought that was really exciting and liberating as an actor because you didn’t know where this guy was gonna go.”Nick’s fatal flaw – and one that Affleck seems to perfectly embody – is that he constantly underestimates the women in his life at every turn: from Ivy Leaguer Amy, his loyal and much wiser twin sister, and his opportunistic mother-in-law to the female cop in charge of Amy’s case, his naïve mistress and the female TV news commentators who feed on his outward signs of weakness for ratings.

He doesn’t even know to run away as fast as he can when an unknown lady at an event for search volunteers coyly offers to bake him one of her famous Frito pie casseroles.

Nick’s most telling line? “I’m so sick of being picked apart by women.”

Fincher – an expert at zeroing in on the vulnerability of men – has spied a side to Affleck the actor that few directors have capitalized on. He is the perfect beta counterpart to Michael Douglas, who in the ‘80s and ‘90s made his career out of embodying the modern alpha male often victimized by women in such gender-clash classics as “The War of the Roses,” “Fatal Attraction,” “Basic Instinct” and “Disclosure.”

Fincher is highly aware of how good Douglas is at portraying a powerful guy who allows himself to get duped, having worked with him in 1997’s “The Game.” Now, Affleck represents a variation of that type for a post-recession, social-media obsessed era.

This may be good news for comic-book fans who have been divided over Affleck taking over the role as billionaire Bruce Wayne in the 2016 sequel “Batman v. Superman: Dawn of Justice.” Maybe he will be encouraged to summon some of the darker emotional turmoil that graced one of his best-received past performances: as George Reeves, the troubled actor who played Superman on ‘50s TV in 2006’s “Hollywoodland.”

Here are five ways that “Gone Girl” craftily capitalizes on Affleck’s past:1. He’s no hero.

Audiences, and often critics, have never accepted Affleck as a typical do-gooder who saves the day despite his tall, dark and handsome appearance. The actor certainly didn’t start off that way when he played an anti-Semite student in “School Ties,” a bully in 1992’s “Dazed and Confused” and a less than-enlightened comic-book writer in love with a lesbian in 1997’s “Chasing Amy.”

All that changed after he and buddy Matt Damon won an original screenplay Oscar for “Good Will Hunting,” also in 1997, which provided them with onscreen breakout roles. Soon, Affleck found himself in studio land fighting an asteroid hurtling towards Earth in 1998’s “Armageddon” and as a fighter pilot in the much-derided “Pearl Harbor” in 2001. His take on CIA agent Jack Ryan in 2002’s “The Sum of All Fears” couldn’t match Harrison Ford, who had starred in the franchise’s two previous entries. And even Affleck has called “Daredevil,” in which he played a blind crusader inspired by his favorite comic book a kid, “The only movie I regret.” Fincher turns Affleck’s lack of believability in these types of heroic roles into a strength as Nick continually has a hard time convincing anyone of his innocence, save for maybe his pet cat.2. He needs a strong mentor.

There is a reason why Affleck has won Oscars for writing and producing, but has never been nominated for his thespian skills. He needs a savvy director who challenges his smarts more than simple-minded studio popcorn assignments. Consider producer Scott Rudin and Brit Roger Michell, who wisely capitalized on Affleck’s ability to summon smarmy charm as an arrogant attorney pitted against a desperate Samuel L. Jackson in the 2002 road-rage thriller “Changing Lanes.”

Fincher once again plays off audience pre-conceptions of Affleck in the “Gone Girl” scene when Tyler Perry’s Johnnie Cochran-style celebrity lawyer rehearses with Nick before he goes on air to publicly plead his case via a female interviewer. Every time his client sounds insincere, Perry’s Tanner Bolt pelts Nick with a Gummi Bear. A lot of Gummi Bears. As a result, the audience laughs both in recognition and approval, and is won over by Nick as well.

3. He knows how to deliver a performance under pressure.

Nick manages to sway the social-media hordes by owning up to his faults and acting humble during that interview. Similarly, Affleck shrewdly swayed public opinion for his own benefit after he was snubbed by the snobby Oscar directors branch even as “Argo” was nominated for seven other Academy Awards.

When he won the directing honor at the Critics’ Choice awards two days later, Affleck won over the audience – as well as some sympathy Oscar votes for “Argo” — by cleverly referencing being overlooked in his acceptance speech. He began, “Thank you very much. I would like to thank the Academy.” He then quickly added, “I’m kidding, I’m kidding! This is the one that counts.”

4. He has been a media target. If anything in his life prepared Affleck to be a character who is persecuted by tabloid outlets and pursued by the paparazzi, it was his time in the spotlight when his relationship with his onetime fiancée, singer/actress Jennifer Lopez, overshadowed his movie efforts.

Not only that, those who suffered through their romantic maneuvers in the 2003 turkey “Gigli” might have had an unwanted flashback during “Gone Girl’s” initial sex scene between Nick and Amy: When Lopez uttered the immortal line, “Gobble, gobble.” If that doesn’t stir up enough unwanted memories, just watch this notorious music video for Lopez’s hit, “Jenny From the Block,” which captures Bennifer in the act of cavorting.

5. He works well with others. Affleck the director is Fincher’s equal when it comes to spot-on casting. It’s great to see him reunite in a key scene in “Gone Girl” with the terrific Scoot McNairy, who contributed greatly to the climatic airport sequence in “Argo” as one of the escaping hostages.